<!DOCTYPE html>
<link rel=author href="mailto:jarhar@chromium.org">
<link rel=help href="https://drafts.csswg.org/selectors-4/#open-state">
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="../../resources/testdriver.js"></script>
<script src="../../resources/testdriver-vendor.js"></script>
<style>

dialog:open + #afterdialog,
details:open + #afterdetails,
select:open + #afterselect {
  will-change: text-decoration;
}

</style>

<dialog>dialog</dialog>
<p id="afterdialog"></p>

<details>details</details>
<p id="afterdetails"></p>

<select>
  <option>one</option>
</select>
<p id="afterselect"></p>

<script>
test(() => {
  const dialog = document.querySelector('dialog');
  const after = document.getElementById("afterdialog");
  assert_false(dialog.matches(':open'),
    ':open should not match when the dialog is closed.');
  assert_equals(getComputedStyle(after).willChange, "auto",
                ":open style should not be applied when the dialog is closed");

  dialog.show();
  assert_true(dialog.matches(':open'),
    ':open should match after dialog.show().');
  assert_equals(getComputedStyle(after).willChange, "text-decoration",
                ":open style should be applied after dialog.show()");

  dialog.close();
  assert_equals(getComputedStyle(after).willChange, "auto",
                ":open style should not be applied when the dialog is closed (2)");

  dialog.showModal();
  assert_true(dialog.matches(':open'),
    ':open should match after dialog.showModal().');
  assert_equals(getComputedStyle(after).willChange, "text-decoration",
                ":open style should be applied after dialog.showModal()");

  dialog.close();
  assert_equals(getComputedStyle(after).willChange, "auto",
                ":open style should not be applied when the dialog is closed (3)");
}, 'The dialog element should support :open.');

test(() => {
  const details = document.querySelector('details');
  const after = document.getElementById("afterdetails");
  assert_false(details.matches(':open'),
    ':open should not match when the details is closed.');
  assert_equals(getComputedStyle(after).willChange, "auto",
                ":open style should not be applied when the details is closed");

  details.open = true;
  assert_true(details.matches(':open'),
    ':open should match when the details is open.');
  assert_equals(getComputedStyle(after).willChange, "text-decoration",
                ":open style should be applied when the details is open");
}, 'The details element should support :open.');

promise_test(async () => {
  const select = document.querySelector('select');
  const after = document.getElementById("afterselect");
  assert_false(select.matches(':open'),
    ':open should not match when the select is closed.');
  assert_equals(getComputedStyle(after).willChange, "auto",
                ":open style should not be applied when the select is closed");

  await test_driver.click(select);
  await new Promise(requestAnimationFrame);
  assert_true(select.matches(':open'),
    ':open should match when the select is open.');
  assert_equals(getComputedStyle(after).willChange, "text-decoration",
                ":open style should be applied when the select is open");
}, 'The select element should support :open.');
</script>
